Hello Yuchin

I am interested in this topic too. As I know, you can't remove the teflon
layer by acetone, maybe you could try some perfluroinated solvents, for
example Freon.

Another possibility could be using plasma, the question is what kind of gas
you should use and if you can remove the teflon layer completely. Anyhow
please inform me if you have some good solutions. Thanks!

Regard
Xuemei


-----Ursprüngliche Nachricht-----

Von: [email protected] [ 
mailto:[email protected]] Im Auftrag von Yuchin
Gesendet: Donnerstag, 16. März 2006 23:33
An: [email protected]
Betreff: [mems-talk] teflon deposit problem

Hello all,

I have some questions about depositing teflon(or teflon-like)

1. If there are some cavites  on silicon substrate.  I want to deposit
teflon on Si surface but not on Si3N4

  (Si3N4 is in the cavity, as the figure).

   How do I remove the teflon on Si3N4 easily after the CVD teflon
process(or other teflon deposit process)??

   I know that the adhesion between teflon and Si3N4 is bad, may I immerse
the wafer in acetone(or something else)

   to remove the teflon on Si3N4??

   I can't use photolithography process, because the height of Si3N4
patterns are  much lower than Si. PR can't coater well on it.


2. After removing the teflon on Si3N4,  I will use RIE(CF4) to remove Si3N4.

   Will CF4 plasma attack teflon (I need the hydrophobic property of
teflon)???